Edited by Vafa Rahimi-Movaghar .

96 pages .Open Access .

The purpose of this book is to review all types of pituitary adenoma and describe the symptoms, epidemiology, diagnosis, management, outcome and complications of them.

Pituitary adenomas are typically benign, slow-growing tumors that arise from cells in the pituitary gland. The pituitary gland lies below the optic system, primarily the optic chiasm, and below the optic nerves and optic tracts. Thus, pituitary adenomas, the most common tumors of the hypophysis, can compress optic system and some of the main symptoms and signs in patients are visual. Therefore, measurement of visual acuity, visual fields, ophthalmoscopy and the use of Optical Coherence Tomography has a significant role in diagnosis and periodic evaluation of the patient.

Pituitary adenomas are classified based on hormone secretory products. But nonfunctioning adenomas are endocrine-inactive tumors. Because of physiologic effects of excess hormones, the functioning tumors present earlier than non-functioning adenomas. On the other hand, the mass effect from large pituitary adenomas may lead to the pressure symptoms, such as headaches, visual field defects, cranial nerve

deficits, hypopituitarism, pituitary apoplexy or stalk effect.

The molecular mechanisms underlying the development and progression of pituitary adenoma have not yet been clearly defined. However, immunohistochemistry and ultrastructural analysis developed new insights into the pathogenesis of these tumors.

The finding of specific serum markers in patients with pituitary adenoma will help physicians in the accurate diagnosis and specific treatment of patients in the future.

Diagnostic MRI of the sellar region constitutes one of the most challenging subjects in neurooncology. T1- and T2-weighted MRI in coronal and sagittal planes with and without paramagnetic contrast medium is the method of choice for imaging of the pituitary gland and the perisellar area.

During the past two decades, a number of new procedures for radiation dose delivery and fractionation have become extensively accessible. The most important progress has been in the use of stereotactic procedures to make radiotherapy targeting relatively simple and very precise. This has permitted the application of single fraction high-dose irradiation entitled stereotactic radiosurgery for brain tumors which can be given as an adjuvant or as a specific treatment modality for pituitary adenomas in patients who have had recurrence after microsurgery, or if complete tumor removal has not been possible.

Finally, visual testing, endocrine evaluation and MRI are three main tools in the pre and post treatment assessment of patients with pituitary adenoma. Considering all modalities of treatment (medical, surgical, or radiotherapy) selected for management of patients, visual assessment together with endocrine and imaging is essential in short and long term evaluation of tumors of the hypophysis.

I want to thank Ms Maja Bozicevic for helping me trough the process, InTech for giving me opportunity to work as an Editor and Prof. Ed Laws for his support.

Vafa Rahimi-Movaghar, MD

Associate professor of Neurosurgery

Vice-Chairman of Sina Trauma and Surgery Research Center, Department of